A second suspected incident of police violence during anti-G20 protests earlier this month in London is being investigated after new video footage emerged.Aired on the website YouTube, the pictures show a woman protester taunting an officer. After initially retaliating by apparently striking her in the face, the officer is then seen hitting her across the legs. It comes a week after another police officer was suspended pending further investigations after he was caught on camera pushing a newspaper salesman to the ground. Forty-seven-year old Ian Tomlinson later died of a heart attack at the scene. Both this and the latest incident are being investigated by the Independent Police Complaints Commission.